Retiring cam mechanism for unlatching elevator doors



g- 1950 F. M. ERLER RETIRING CAM MECHANISM FOR UNLATCHING ELEVATOR DooRs Filed March 24, 1948 Patented Aug. 29, 1950 RETIRING =CAM MECHANISM FOR UNLATOHIN'G ELEVATOR DOORS Fred M. Erler, Chicago, Ill. Application March 24, 1948, Serial No. 16,756

Claims. 1

7 This invention relates to elevators and more particularly to retiring cam mechanisms for unlatching elevator doors.

In the prior art, retiring cam mechanisms have generally been of a gravity actuated type with a torque motor mounted on the elevator and connected to the mechanism for retiring and the use of buffers or shock absorbers which frequently are broken and must be replaced. Furthermore, in the retired position of the cam,

itfswin'gs on its linkage causing wear and dam- -age to the parts.

-A general object of the present invention is to design a, retiring cam mechanism for elevators which is spring actuated to operative position and is resiliently maintained in said position without the use of special buffers.

' Another object of the invention is to resiliently "control the mechanism in the retired as well as the operative position thereof.

Still another object of the invention is to eliminate swinging of the cam by providing means for guiding the latter in rectilinear movement to advance and retired positions.

A further object of the invention is to simplify the construction of the mechanism and eliminate the conventional torque motor and to devise a .mechanism which may be retired by a solenoid type motor which may be equipped, if desired, with a conventional dashpot.

' Another object of the invention is to devise a retiring cam mechanism such as above'described, .in which the cam is provided with beveled faces to ride over the door latches in the event that the solenoid, for some reason, becomes inoperative.

Still another object of the invention is to devise a retiring cam mechanism such as above described in the form of a unitary assembly'ineluding a cam, means for advancing the same, and means for retiring the cam. The assembly is adapted for application to and removal from an elevator as a unit thereby facilitating installation and repair of the mechanism.

The foregoing and other objects and advantages of the invention will become apparent from a consideration of the following specification and the accompanying drawings, wherein:

Figure 1 is a perspective view taken from the interior of an elevator having a preferred embodiment of the invention applied thereto, the elevator doors being open and portions of the elevator and the elevator shaft being broken away; and

Figure 2 is a side elevational view of the retiring cam mechanism taken from the exterior of the elevator, the doors being'closed.

1 Describing the invention in detail, the novel retiring cam mechanism is illustrated as applied to a conventional elevator 2 operating within a shaft 5 comprising a doorway 6 defined at each side thereof by panels 8. Between the panels 8 is a guide channel ii! for top and bottom doors i2 and I4 connected together in a conventional manner by linkage (not shown) causing the doors to move in unison to open and closed positions. Thus latching of either door in closed position, as hereinafter discussed, latches both doors as will be readily understood by those skilled in the art.

For the sake of simplicity a conventional latch mechanism is diagrammatically shown at 16, said mechanism comprising a latch member l8 pivoted at 26 to a beam 24 connected to the outer panel 8. The member it carries a roller 25 and is spring pressed to latched position by a spring diagrammatically indicated at 28. The spring is seated against a beam 39 defining one side of the shaft 4. At the upper end of the member 58 is formed a lug or projection 32 bearing against a shoe SA pivotally connected at 35 to a plunger 38 reciprocal Within a guide casing id which may contain, if desired, conventional switch means (not shown), commonly known in the art as an interlock, for closing the elevator control circuit when the doors 1?.

and. [4 are locked.

in the closed position shown in Figure 2.

It will be understood by those skilled in the art thatthe door latching mechanism i5 above described is diagrammatically illustrated for the sake of clarity, and any conventional cam actuated latch mechanism may be utilized with the novel retiring cam mechanism hereinafter described.

The retirin mechanism generally designated 44 is shown in advance or operative position in Figure 1 with the doors l2 and i4 open and the mechanism as shown in Figure 2 is in retired or inoperative position with the doors closed.

The mechanism 44 comprises a cam with top and bottom diagonal surfaces 48 and 56 serving a purpose hereinafter described, in connection with the operation of the device. The cam is mounted on one or more rods or plungers 63, each of which is slidably guided within a hollow guide bracket 62 secured as at 68 to a support bar 79 adapted for removable connection in any desired manner as by bolts or rivets "H' The plungers are connected by a bar or bridge I2 which is to one corner of the elevator 2.

conventional dashpot 84 for damping movement of the plunger 32.

In operation of the novel retiring cam mechanism, when the elevator is actuated to the doorway 6 the doors l2 and [4 are locked, and the solenoid 83 retains the cam 46 in retired position until the circuit through the elevator actuating motor (not shown) is broken, whereupon the solenoid is deenergized, and the springs '14 urge the cam 45 to advance position against the roller 26, pivoting the latch member 18 from its engagement with the finger 42, to accommodate opening of the doors l2 and M as shown in Figure 1. The bar [2 acts as a stop for the cam 46 and is maintained tightly against the brackets 62 in the advance position of the cam.

With the doors closed, the solenoid is again energized to retire the cam 46 as shown in Figure 2, whereupon the latch member I8 is spring pressed to latched position in engagement with the finger 42, and the switch plunger 38 is actuated to accommodate closing of the elevator control circuit.

In the event that the solenoid fails to operate, the beveled surfaces 48 and 50 of the cam 46 are adapted to ride over the rollers 26 of the various doors, as the elevator operates within the shaft, thereby preventing damage to the parts until the inoperative condition of the solenoid can be corrected.

Thus it will be understood that I have devised a novel retiring cam mechanism in which movement of the cam is resiliently restrained in both the advance and retired position thereof and in which uncontrolled swinging of the cam is eliminated by the provision of means for guiding the same in rectilinear movement throughout its operating cycle. Furthermore, the novel mechanism is so constructed as to accommodate action of the cam by a solenoid rather than a torque motor, thereby simplifying the operation and construction of the device.

It will be understood that I do not Wish to be lim ted b the exact embodiment of the device shown which is merely by way of illustration and not limitation, as various and other forms of the device will, of course, be apparent to those skilled in the art, without departing from the spirit of the invention or the scope of the claims.

I claim:

1. A retiring cam mechanism for releasing door latches in an elevator shaft, comprising a unitary assembly including a support structure adapted for securement to an associated elevator operating within said shaft, a cam carried by said structure and adapted in advance position to release said latches, and actuating means for said cam carried by said structure for advancing and retiring said cam, said structure, together with said cam and actuating means being at tachable and detachable as a unit to said elevator.

2. A retiring cam mechanism for releasing door latches in an elevator shaft, comprising a support member adapted for removeable connection to an associated elevator within said shaft, a guide bracket carried by said member, a rod slidably fitted in said bracket for rectilinear movement therein, a cam carried by said rod, spring means reacting against said member and said rod for urging the cam to advance position to release said latches, and power means carried by said member for retiring said cam against the resistance of said spring means.

3. A retiring cam mechanism for releasing door latches in an elevator shaft, comprising a retiring cam mechanism including a support member having spaced guide brackets, spaced rods slidably fitted in said brackets, a cam carried by said rods at one side of said brackets, a bar connecting said rods at the other side of said brackets, tension spring means connected between the bar and said member for urging said cam to advance, latch engaging position, and power means carried by said member and operatively connected to said cam for retiring the same to inoperative position, said member being removeably secured to said elevator, whereby said mechanism may be removed as a unit for repair and replacement.

4. A retiring cam mechanism for releasing door latches in an elevator shaft, comprising a. unitary cam mechanism, including a support member, a cam moveably mounted on said member for movement to advance, latch engaging position and to retired, inoperative position, spring means carried by said member and operatively connected to said cam for urging the same to latched position, and power means carried by said member for actuating the cam to retired posi.ion against the resistance of said spring means, whereby movement of said cam is spring resisted in both of said positions, said cam, said spring means, and said power means being carried by said support member as a unit which may be attached to an associated elevator and detached therefrom.

5. A retiring cam mechanism on an elevator for releasing door latches in an elevator shaft comprising a cam adapted in advance position to engage said latches and adapted in retired position to clear said latches, spring means operatively connected to the cam for urging the cam to advance position, power means operatively connected to the cam for actuating the same in ret red position, and guide means for restricting said cam to substantially linear movement to its advance and retired positions.

6. A retiring cam mechanism on an elevator for releasing door latches in an elevator shaft comprising a cam adapted in advance position to engage said latches and adapted in retired position to clear said latches, a rod connected to said cam, guide means carried by the elevator for confining said rod against movement other than rectilinear movement with said cam, spring means operatively connected to the cam for urging it to advance position, and power means operatively connected to the cam for urging it to retired position against the resistance of said spring means.

7. A retiring cam mechanism on an elevator for releasing door latches in an elevator shaft comprising a cam adapted in'advance position to engage said latches and adapted in retired position to clear said latches, a lever pivoted to the elevator and to the cam for actuation thereof, cooperating guide means carriedby the elevator and cam for restraining the latter against other than rectilinear movement during actuation thereof, power means connected to the lever for operation thereof, and spring means connected to the cam for advancing the same after release of said power means.

8. A retiring cam mechanism on an elevator for releasing door latches in an elevator shaft comprising a cam adapted in advance position to engage said latches and adapted in retired position to clear said latches, a guide bracket carried by the elevator, a rod slidably fitted in said bracket, a cam carried by said rod for movement therewith to advance and retired positions, stop means carried by the rod for engagement with the bracket to limit advance movement of the cam, spring means operatively connected to the cam for urging the same to advance position and for urging said stop means against said bracket, and power means carried by the elevator for retiring the cam against the resistance of said spring means.

9. A retiring cam mechanism in the form of a unitary assembly adapted to be mounted on an elevator for releasing door latches in an elevator shaft, said assembly comprising a substantially rigid support structure, a cam moveably mounted thereon, means mounted on said structure for advancing and retiring said cam, and means for connecting said structure to an associated elevator, said assembly being attachable and detachable as a unit with respect to said elevator.

10. A retiring cam mechanism in the form of a unitary assembly adapted to be mounted on an elevator for releasing door latches in an elevator shaft, said assembly comprising a support member, a cam, means carried by said member and cam for guiding the latter in rectilinear movement to advance and retired position, power means mounted on said member and operatively connected to the cam for actuating the same to advance position, and means carried by said member for actuating the cam to retired position after release of said power means.

FRED M. ERLER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 910,654 Evans Jan. 26, 1909 1,799,600 Nell Apr. 7, 1931 

